I have added in Magento_Contact
module custom field with order number:
<div class="field telephone">
<div class="control">
<input placeholder="<?php echo __('Your Phone') ?>" name="telephone" id="telephone"
title="<?php /* @escapeNotVerified */
echo __('Phone Number') ?>" value="" class="input-text" type="text"/>
</div>
</div>
<div class="field ordernumber">
<div class="control">
<input placeholder="<?php echo __('Order Number') ?>" name="ordernumber" id="ordernumber"
title="<?php /* @escapeNotVerified */
echo __('Order Number') ?>" value="" class="input-text" type="text"/>
</div>
</div>
screen: https://prnt.sc/s5fgtu
But when I sent a message via this form after filling this custom field (order number), when I receive a message from this contact module then this field is not displayed.
screen: https://prnt.sc/s5fh54
Any solution how to do?